YouTube content is created by human beings. There is an absolute bound to that (record everything everybody does all day long). No, its not geometric and can never be, right?

Storage and network charges are already pennies per terabyte-day. So currently and in the forseeable future, YouTube's costs will probably be administrative.

And that's all beside the point. There's not hard 24-hour one-channel limit to what YouTube can 'broadcast'. So their model is completely unlike a traditional TV station. So that analogy is flawed. So we can conclude, YouTube's decision to show (or not show) anything is based on completely different criterion. Pedantry notwithstanding.